2ENA Chapter 13 Electrical Systems Part III

2ENA Chapter 13 Electrical Systems Part III

Multiple Choice

The diagram above represents an electric circuit consisting of four resistors and a 12-volt battery.

What is the current measured by ammeter A shown in the diagram?

• 4.0 A

• 72 A

• 2.0 A

• 0.50 A

Multiple Choice

The diagram above represents a circuit consisting of two resistors connected to a source of potential difference.

What is the current through the 20.-ohm resistor?

• 12 A

• 6.0 A

• 4.0 A

• 0.25 A

Multiple Choice

The total resistance of this circuit is 

• 25.7 ohms
• 315 ohms
• 324 ohms
• 90 ohms

Multiple Choice

The total current going through the battery of this circuit is

• 0.35 amps
• 0.0286 amps
• 0 amps
• 9 amps

Multiple Choice

The total current through this circuit is

• 0.02 amps
• 0.09 amps
• 50 amps
• 9 amps

Multiple Choice

The total resistance in this circuit is 

• 100 ohms
• 450 ohms
• 400 ohms
• 30 ohms

Multiple Choice

The total resistance of this circuit is 

• 25.7 ohms
• 315 ohms
• 324 ohms
• 90 ohms

Multiple Choice

What resistance is needed to cause a 50A current flow because of a 500V battery?

• 10Ώ
• 5Ώ
• 2500Ώ
• 550Ώ

Multiple Choice

What voltage is needed to cause a 2A current flow through a 10Ω resistor?

• 5V
• 0.2V
• 20V
• 200V

Multiple Choice

Voltage divided by Resistance

(V / R)

• Current

• Power

• Ohms

• Watts

Multiple Choice

Current times Resistance equals
 (I X R)

• Power
• Voltage
• Amperage
• Ohm

Multiple Choice

What is the Voltage of a circuit that has a resistance of 5 Ω and a current of 2 A?

• 25 V
• 10 V
• 2.5 V
• 0.4 V

Multiple Choice

What is Resistance?

• The flow of electrons
• Electric potential difference
• A battery
• The ability to reduce the flow of electrons

Multiple Choice

What is resistance measured in?

• Ω (Ohms)
• V (Volts)
• A (Amps)
• W (Watts)

Multiple Choice

What size resistor would produce a 3 Amp current flow with a 12 Volt battery

• 1 Ohm
• 3 Ohms
• 4 Ohms
• 12 Ohms

Multiple Choice

The diagram shows a _____.

• circuit breaker

• fuse

• rheostat

• switch

Multiple Choice

There is a damaged insulation.

The best thing to do is to _____.

• cover the part with tape

• call an electrician to replace

• add a fuse

• add an earth wire

Multiple Choice

This diagram shows _____.

• a circuit breaker

• overloading of a socket

• a melting fuse

• an electrocution hazard

Multiple Choice

The S.I. unit for Power is _____.

• watt

• joule

• ampere

• volt

Multiple Choice

The _____ melts and breaks the circuit to protect the appliance when the current is too high.

• bulb

• fuse

• circuit breaker

• earth wire

Multiple Choice

A/An _____ is NOT a safety electrical device.

• fuse

• circuit breaker

• earth wire

• voltmeter

Multiple Choice

Two-pin plugs do NOT have the _____ wire.

• Live

• Neutral

• Earth

Multiple Choice

Which one CANNOT help to prevent electrocution?

• Do not use electrical gadgets in wet places

• Call electrician to replace damaged wires

• Overload an electrical socket

• Switch off and plug out plugs before cleaning appliances

Multiple Choice

1 kWh costs 20 cents.

Using a 3 kW lamp for 2 hours will cost _____ cents.

• 6

• 40

• 60

• 120

Multiple Choice

An electric iron has a power rating of 1800 W.

This means _____ is converted in 1 second.

• 1800 J

• 1800 A

• 1800 V

• 1800 W

Fill in the Blank

A 2400 W water heater was used for 15 minutes.

Calculate the electrical energy in kWh consumed by the water heater.

Fill in the Blank

A 1200 W iron was switched on for 3 hours.

Calculate the electrical energy consumed by the iron in kWh.

Fill in the Blank

A 1.2 kW microwave oven was used for 2 hours.

What is the electrical energy in kWh consumed by the oven?

Fill in the Blank

A 0.40 kW lamp was turned on for 8 hours.

What is the electrical energy in kWh consumed by the lamp?

Multiple Choice

How much does it cost to light 6 100 W light bulbs for 6 hours if the price of electrical energy is $0.09/kWh?

• $4.00
• $6.24
• $3.24
• $5.24

Multiple Choice

A kilowatt (kW) is how many watts?

• 10

• 50

• 100

• 1000